MicroRNA-218-5p-Ddx41 轴通过下调帕金森病小鼠模型中 I 型干扰素反应来抑制小胶质细胞介导的神经炎症。

MicroRNA-218-5p-Ddx41 axis restrains microglia-mediated neuroinflammation through downregulating type I interferon response in a mouse model of Parkinson's disease.

机构信息

Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.

Department of Neurology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China.

出版信息

J Transl Med. 2024 Jan 16;22(1):63. doi: 10.1186/s12967-024-04881-w.

DOI:10.1186/s12967-024-04881-w

PMID:38229084

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC10792813/

Abstract

BACKGROUND

Parkinson's disease (PD) is a neurodegenerative disorder characterized by the loss of dopaminergic (DA) neurons in the substantia nigra (SN). Microglia-mediated neuroinflammation has been largely considered one of main factors to the PD pathology. MicroRNA-218-5p (miR-218-5p) is a microRNA that plays a role in neurodevelopment and function, while its potential function in PD and neuroinflammation remains unclear.

METHODS

We explore the involvement of miR-218-5p in the PD in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model. The miR-218-5p agomir used for overexpression was delivered into the substantia nigra (SN) by bilateral stereotaxic infusions. The loss of dopaminergic (DA) neurons and microglial inflammation in the SN was determined using Western blotting and immunofluorescence. Motor function was assessed using the rotarod test. RNA sequencing (RNA-seq) was performed to explore the pathways regulated by miR-218-5p. The target genes of miR-218-5p were predicted using TargetScan and confirmed using dual luciferase reporter assays. The effects of miR-218-5p on microglial inflammation and related pathways were verified in murine microglia-like BV2 cells. To stimulate BV2 cells, SH-SY5Y cells were treated with 1-methyl-4-phenylpyridinium (MPP) and the conditioned media (CM) were collected.

RESULTS

MiR-218-5p expression was reduced in both the SN of MPTP-induced mice and MPP-treated BV2 cells. MiR-218-5p overexpression significantly alleviated MPTP-induced microglial inflammation, loss of DA neurons, and motor dysfunction. RNA sequence and gene set enrichment analysis showed that type I interferon (IFN-I) pathways were upregulated in MPTP-induced mice, while this upregulation was reversed by miR-218-5p overexpression. A luciferase reporter assay verified that Ddx41 was a target gene of miR-218-5p. In vitro, miR-218-5p overexpression or Ddx41 knockdown inhibited the IFN-I response and expression of inflammatory cytokines in BV2 cells stimulated with MPP-CM.

CONCLUSIONS

MiR-218-5p suppresses microglia-mediated neuroinflammation and preserves DA neurons via Ddx41/IFN-I. Hence, miR-218-5p-Ddx41 is a promising therapeutic target for PD.

摘要

背景

帕金森病（PD）是一种神经退行性疾病，其特征是黑质（SN）中的多巴胺能（DA）神经元丧失。小胶质细胞介导的神经炎症被认为是 PD 病理学的主要因素之一。MicroRNA-218-5p（miR-218-5p）是一种在神经发育和功能中发挥作用的 microRNA，但其在 PD 和神经炎症中的潜在功能尚不清楚。

方法

我们通过双侧立体定向注射将 miR-218-5p 激动剂递送到 SN 中，以探讨 miR-218-5p 在 1-甲基-4-苯基-1,2,3,6-四氢吡啶（MPTP）诱导的小鼠模型中的作用。用 Western blot 和免疫荧光法测定 SN 中多巴胺能（DA）神经元的丢失和小胶质细胞炎症。用旋转棒试验评估运动功能。进行 RNA 测序（RNA-seq）以探索由 miR-218-5p 调节的途径。使用 TargetScan 预测 miR-218-5p 的靶基因，并使用双荧光素酶报告基因测定法进行确认。在鼠类小胶质细胞样 BV2 细胞中验证 miR-218-5p 对小胶质细胞炎症和相关途径的影响。为了刺激 BV2 细胞，用 1-甲基-4-苯基吡啶鎓（MPP）处理 SH-SY5Y 细胞，并收集条件培养基（CM）。

结果

MPTP 诱导的小鼠 SN 中和 MPP 处理的 BV2 细胞中 miR-218-5p 的表达均降低。miR-218-5p 的过表达显著减轻了 MPTP 诱导的小胶质细胞炎症、DA 神经元丧失和运动功能障碍。RNA 序列和基因集富集分析显示，I 型干扰素（IFN-I）途径在 MPTP 诱导的小鼠中上调，而过表达 miR-218-5p 则逆转了这种上调。荧光素酶报告基因测定证实 Ddx41 是 miR-218-5p 的靶基因。在体外，miR-218-5p 的过表达或 Ddx41 的敲低抑制了 MPP-CM 刺激的 BV2 细胞中的 IFN-I 反应和炎性细胞因子的表达。